Orthotic braces are generally used for the support and bracing of weak or ineffective muscles or joints, especially for the support of knees or other joints of the limbs. An orthotic knee brace is generally an orthotic leg brace having an upper section which is removably attached to the upper leg and a lower section removably attached to the lower leg. The two sections may be hinged together at their intersection near the knee to allow for articulation with the knee movement while providing support for the knee.
Orthotic braces may be employed in long-term orthopedic devices for patients in the correction of permanently weakened or ineffective leg muscles, bones or knee joints. In this regard, a brace such as a knee brace would generally be lockable into a rigid and fully extended position where the upper and lower sections are roughly parallel to each other and to the axis of the extended limb. This arrangement allows for the support of the knee joint when it is in a completely extended and full weight-beating position such as when the brace user is standing or walking. Such braces may also be releasable from their fully extended position to articulate with the flexion of the joint such as when the user is sitting. Orthotic braces of this type may also be employed for use with lower extremity prosthetics.
Similar orthotic braces may be employed in rehabilitation devices for patients recovering from leg trauma such as broken bones, ligament damage, muscle damage, knee joint damage, sports injury, related surgery injury and the like. In this regard, the brace may be fixed in a rigid, fully extended position as above to immobilize the leg or knee joint and provide rigid support for the leg or knee, without being releasable to allow articulation of the knee joint. Such orthotic brace rehabilitation devices may be replaced with braces such as those used for long-term orthopedics which allow for articulation with the limb movement during the course of patient rehabilitation.
Orthotic braces of the type referred to immediately above are disclosed, for example, in the Prosthetics and Orthotics Catalogue distributed by Keiai Orthopedic Appliance Co., Ltd. This reference provides representatives of a variety of lower limb orthotic braces currently available.
Keiai knee braces generally comprise above-knee and below-knee bars respectively attachable to the upper and lower leg of the user and which are pivotally attached to each other at a hinged joint aligned near the user's knee joint. These braces are movable about the hinge joint from an extended position corresponding to a fully vertical or straightened leg, to an articulated position corresponding to the flexion of a bent leg. The Keiai braces are further constructed so that cooperation of the upper and lower bar members only allows for articulation between the fully extended position and movement in one direction, corresponding to the normal articulation of a leg. In this regard, the braces prevent over-center operation, or in other words, prevent the knee joint from traveling past its fully extended position.
Orthotic braces such as knee braces available under the Keiai trade name are generally attached to a patient's leg by use of thigh and calf bands. These bands may be made up of a variety of materials such as leather, plastics, metals or curable composite materials and are generally permanently fixed to the brace members after those brace members have been bent into S-shapes to conform with the contours of the patient's leg. The brace members may also be attached to a patient's leg by being integrated into a cast or other rehabilitative device.
Keiai knee braces are available in a variety of models ranging from those which are free hinging between fully extended and articulated positions, to those including locking devices which act to lock the brace in the fully extended position. Typical locking mechanisms include ring-slide locks, french locks, drop locks and drop locks with stoppers.
Drop locks as disclosed by the Keiai reference, such as the parts numbered K-109 and K-110, generally comprise a slidable collar arranged on the upper bar member of the brace. When the brace is in an articulated position, the collar is moved on the upper bar member to a non-locking position on that member generally well above the hinge joint of the brace. When the brace user is in a vertical or standing position, the collar travels down the brace member under the influence of gravity to a locked position where the collar engages a cam surface on the lower member arranged above the hinge joint. In the locked position the collar rests just above the hinge joint of the brace and prevents the lower member from moving in relation to the upper member.
Once a Keiai brace with a slidable collar drop lock mechanism is integrated into an assembled orthotic device, that locking mechanism is generally not removable or detachable without the subsequent removal and disassembly of the orthotic brace device. In this regard, a brace user no longer desirous of the locking feature provided by the collar mechanism must incur the time and cost of obtaining a new brace device assembled without the inclusion of the locking mechanism. Further, such locking devices are not attachable to an assembled orthotic brace device, such as where a brace user desires the addition of the locking feature to an existing brace. Here, as above, the brace user must incur the added time and expense of obtaining a new orthotic device having a locking mechanism in place.
French locks as disclosed by Keiai, such as the pans numbered K-103 and K-104, generally comprise a lever attached to the upper member of a brace which cooperates with a notched surface on the lower brace member. Here, the notched surface is arranged above the hinge joint and engages the lever in a locked position above the hinge joint when the brace is in its fully extended position. The lever is then releasable out of its locking engagement with the notched surface, allowing the brace to articulate with the flexion of the knee joint.
As with the slidable collar drop lock mechanisms above, the french lock mechanism is generally permanently fixed to an assembled orthotic brace device. In this regard, the french lock mechanism is likewise not readily attachable or detachable on an existing device. A brace user desirous of either obtaining or removing the locking feature provided by the french lock will need to incur the time and expense of having a new orthotic brace assembled with or without the french lock in place.
Ring-slide locks under Keiai, such as the parts numbered K-101 and K-102, are generally improved drop locks where the collar has further means for urging the collar into its locked position. Here, a lock bar is attached to the collar and fixed to the upper brace member by a guide means. A compression spring is arranged between the collar and the lock guide means on the lock bar to urge the collar into its locked position above the brace hinge joint. The lock is releasable by pulling the lock bar upwards, against the spring direction, to slide the collar out of engagement with the lower brace member cam surface.
The additional hardware associated with the lock bar, guide means and compression spring means causes these locking mechanisms to be generally permanently fixed to an assembled orthotic brace device. As above, the lack of removability and attachability of these locking devices to existing braces leads to added time and expense for users wishing to remove or add the french lock device to an existing brace.
Orthotic braces of the type referred to above are further disclosed by the Catalogue of OMNI Scientific, Inc. One such knee brace, available under the Trade name of the OMNI brace, comprises generally the same parts as those disclosed by Keiai with the added feature of an adjustable fixed extension setting for selecting the angular relation of the upper and lower brace members when they are in the fully extended position.
In this regard, the OMNI brace comprises an upper brace member or bar which is pivotally attached to a shackle at its lower terminus where the shackle is arranged generally near the knee joint. The shackle is further adjustably fixed to the upper brace bar in a position such as 0, 10, 20 or 30 degrees relative to the axis of the upper brace bar, thereby preventing the upper brace member from pivoting in relation to the shackle. The OMNI brace shackle is then pivotally attached at its other end to the upper terminus of the lower brace member or bar. In this manner, the fully extended position of the brace is fixed with the axes of the upper and lower brace bars at 180, 170, 160 or 150 degrees relative one another.
With the inclusion of a shackle at the hinged joint of a knee brace, such as in the OMNI brace, prior an locking mechanisms such as those employing slidable collars are inadequate to provide a simple and effective means to lock those braces into a fully extended position. Further, prior art locking devices such as drop rings, slidable collars or french locks are generally not removable from or attachable to an assembled orthotic brace in situ, especially after the brace has been attached to a patient's limb. Accordingly, there has been found to remain a need for further improvements in locking devices for orthotic braces.